自组装半导体碳纳米管薄膜的光电特性

[Article]

物理化学学报(Wuli Huaxue Xuebao )

Acta Phys.-Chim.Sin.2014,30(7),1377-1383

July Received:February 26,2014;Revised:May 6,2014;Published on Web:May 9,2014.∗

Corresponding author.Email:shengwang@;Tel:+86-136********.

The project was supported by the National Key Basic Research Program of China (973)(2011CB933002,2011CB933001)and National Natural Science Foundation of China (61370009,61271051,61321001).

国家重点基础研究发展规划项目(973)(2011CB933002,2011CB933001)和国家自然科学基金(61370009,61271051,61321001)资助

©Editorial office of Acta Physico-Chimica Sinica

doi:10.3866/PKU.WHXB201405093

自组装半导体碳纳米管薄膜的光电特性

赵青靓1

刘旸1,2魏楠1王胜1,

*

(1北京大学电子学系,纳米器件物理与化学教育部重点实验室,北京100871;

2

北京大学前沿交叉学科研究院,北京100871)

摘要:采用自组装的方法制备99%高纯度半导体碳纳米管平行阵列条带,以金属钯和钪为非对称接触电极制

备碳纳米管(CNT)薄膜晶体管(TFTs)器件.主要研究不同沟道长度碳纳米管薄膜晶体管器件的电输运特性和红外光电响应特性,分析了其中的载流子输运和光生载流子分离的物理机制.我们发现薄膜晶体管器件的电学性能和光电性能依赖于器件沟道长度(L )和碳纳米管的平均长度(L CNT ).当沟道长度小于碳纳米管的平均长度时,器件开关比最低;当沟道长度超过碳纳米管平均长度时,随着沟道长度的增加,器件开关比增加,光电流减小.相关研究结果为高纯碳纳米管薄膜晶体管器件在红外光探测器方面的进一步应用提供参考依据.关键词:

碳纳米管;

自组装;非对称接触;光电响应;

红外;

沟道长度;薄膜晶体管

中图分类号:

O649

Photoelectric Characteristics of Self-Assembled Semiconducting

Carbon Nanotube Thin Film s

ZHAO Qing-Liang 1

LIU Yang 1,2

WEI Nan 1

WANG Sheng 1,*

(1Key Laboratory for the Physics and Chemistry of Nanodevices,Department of Electronics,Peking University,

Beijing 100871,P .R.China ;2Academy for Advanced Interdisciplinary Studies,Peking University,Beijing 100871,P .R.China )

Abstract:We used the self-assembly method to form high purity (99%)semiconducting carbon nanotube (CNT)aligned arrays.Thin-film transistors (TFTs)were fabricated with asymmetric Pd and Sc electrodes.We studied the electronic transport characteristics and infrared photoelectronic properties of the TFTs with different channel lengths.The physical mechanism of carrier transport and the dissociation of photoexcited carries are also discussed.We found that the electronic and photoelectronic properties of the TFTs were dependent on the channel length and the average length of the CNTs.The on/off ratio of the device was the lowest when the channel length of the device (L )was less than the average length of the CNTs (L CNT ),and it increased with increasing L when L was larger than L CNT .In addition,the short circuit current of the device also decreased.These results provide an effective reference for further infrared detector applications based on high-purity semiconducting carbon nanotube TFTs.

Key Words:Carbon nanotube;Self-assembly;Asymmetric contact;

Photoelectric response;

Infrared;Channel length;Thin film transistor

1引言

碳纳米管(CNTs)自1991年被发现以来,1在纳

米电子和光电应用领域以其优异的性能和广阔的应用潜力得到了广泛的关注.在电学方面,半导体

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